据世界石油4月15日彭博社报道，美国正在建造一种不会向大气中排放温室气体的新型发电厂，这可能为公用事业公司提供一种在不导致全球变暖的情况下继续燃烧天然气的方式。

Net Power公司计划在美国建造两座天然气发电厂，将所有的排放都收集起来并深埋地下。这家初创公司将其技术授权给了将与农业巨头Archer-Daniels-Midlands Co.合作的开发商8 Rivers Capital公司，以取代伊利诺伊州一家燃煤电厂的部分排放。

对于另一家工厂，8 Rivers与科罗拉多州的Ute Indian Tribe南部部落成长基金合作。这两个项目都将在今年设计和开发，8 Rivers称这需要花费数千万美元。是否继续建设这些厂的最终决定将于2022年做出。

Net Power公司的技术使用一种新型涡轮机在氧气中燃烧天然气，而不是在空气中。因此，该工厂只产生二氧化碳和水副产品。水可以从混合物中冻结，纯净的CO?可以埋在枯竭的油气井或类似的地质结构中。

所需的氧气通过与需要能量的空气分离而获得。但Net Power公司表示，其涡轮机的效率更大，因此，总的来说，该系统的整体效率与将其排放物排放到大气中的先进天然气发电厂相匹配。使用氧气的另一个好处是，Net Power不会产生任何会造成当地空气污染的氮排放。

2018年，这家初创公司在德克萨斯州建立了一个运行良好的试点工厂，可以产生约25兆瓦的电力。伊利诺伊州和科罗拉多州的工厂将成为Net Power的首批商业规模工厂。 每个工厂将能够产生280兆瓦的电力。科罗拉多州的发电厂预计也将使用空气冷却，Net Power公司表示，这将把需水量减少到零。

8 Rivers首席执行官Cam Hosie表示，大项目需要时间。对于快速采用这项技术来说，最重要的是第一个项目的成功。大约还有十几家其他的净电厂处于不同的开发阶段，其中一些计划在美国以外建造。

伊利诺伊州的发电厂会将其排放物注入到现有的CO2井中，该井目前掩埋了乙醇生产设施的排放物。科罗拉多州的工厂尚未决定将其排放物埋在何处，但8 Rivers表示，该发电厂的地点靠近一条CO2管道，该管道扩大了可用于存储碳的面积。

尽管发电厂不会产生任何污染，但环保主义者仍对天然气的持续使用感到担忧。化石燃料的生产和运输确实会导致排放，而依靠天然气的公司将不得不减轻排放。

这两家工厂都将获得美国税收抵免，相当于每吨注入地下的二氧化碳约合50美元。与太阳能和风能情况一样，该税收抵免旨在补贴早期的气候技术，直到它们能够与现有的以化石燃料为基础的现有企业竞争。

每家电厂预计将耗资5亿美元以上，8 Rivers及其合作伙伴将在投资决定截止日期前筹集这笔资金。

郝芬 译自 世界石油

原文如下：

U.S. startup plans to build first zero-emission gas power plants

A new kind of power plant that doesn’t add greenhouse gases to the atmosphere is being built in the U.S., potentially providing a way for utilities to keep burning natural gas without contributing to global warming.

Net Power intends to build two natural-gas power plants in the U.S. that will have all its emissions captured and buried deep underground. The startup licensed its technology to developer 8 Rivers Capital LLC, which will work with agriculture giant Archer-Daniels-Midlands Co. to replace some emissions from a coal power plant in Illinois.

For the other plant, 8 Rivers is working with the Southern Ute Indian Tribe Growth Fund in Colorado. Both projects will be designed and developed this year, which 8 Rivers says requires spending tens of millions of dollars. A final decision on whether to go ahead with the facilities is due in 2022.

Net Power’s technology uses a new kind of turbine to burn natural gas in oxygen, rather than the air. As a result, the plant only produces carbon dioxide and water as a byproduct. The water can be frozen out of the mixture and the pure stream of CO? can be buried in depleted oil and gas wells or similar geological structures.

The required oxygen is secured by separating it from the air, which needs energy. But Net Power says its turbine is more efficient so that, on balance, the overall efficiency of the system matches that of an advanced natural-gas power plant that pumps its emissions into the atmosphere. Another upside of using oxygen is that Net Power plants do not produce any nitrogen emissions, which would cause local air pollution.

The startup built a functioning pilot plant in Texas in 2018 that can generate about 25 megawatts of power. The Illinois and Colorado plants will be Net Power’s first commercial-scale units. Each plant will be capable of generating 280 MW of electricity. The Colorado plant is also expected to use air cooling, which Net Power says will cut the amount of water required to zero.

“Big projects take time,” said Cam Hosie, chief executive officer of 8 Rivers. “The most important thing for the rapid adoption of this technology is going to be that the first projects are successful.” Hosie said that about a dozen other Net Power plants are in various phases of development, with some planned to be built outside the U.S.

The Illinois power plant will inject its emissions into an already existing CO? well, which currently buries emissions from an ethanol production facility. The Colorado plant hasn’t decided where to bury its emissions, but 8 Rivers says that the site of the power plant is close to a CO? pipeline which extends the area available for storing the carbon.

Though the power plant won't produce any pollution, environmentalists are concerned about the continued use of natural gas. The production and transportation of the fossil fuel does lead to emissions, which companies that rely on natural gas will have to mitigate.

Both plants will have access to a U.S. tax credit that amounts to about $50 for each ton of CO? injected into the ground. As in the case of solar and wind power, the credit seeks to subsidize early-stage climate technologies until they can compete with the existing fossil-fuel based incumbents.

Each of the power plants is expected to cost more than $500 million, which 8 Rivers and its partners will look to raise before the investment decision deadline.